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Special ItemsPiping items which are not specifically covered under in any design standards, are treated as special items. There are many such e.g.1. Steam Traps2. Strainers3. Sight Glass4. Hoses5. Flame Arresters

Steam Trap Why Steam Trap What is Steam Trap / P.O.P. Types of Trap

The job of steam trap is to get condensate, air and CO2 out of the system. The desired features a trap should possess are: Effective removal of condensate with minimum steam loss, long life, lesser maintenance & lower cost.

7/9/2013Introduction to Piping Materials1Steam Traps Type of Steam traps:Classified based on three operating principles :Density operated Temperature OperatedKinetic Energy Operateda. Thermostatic trap : Balanced pressure thermostatic traps have a blast discharge with high air venting capacity. Their valve & seat are wide open when cold.

- Bimetallic - Liquid Expansion

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Type of Steam trapsb) Thermodynamic Trap: Thermodynamic traps are the most widely used steam traps, largely due to their small size, wide pressure range, one moving part and resistance to water hammer and corrosion. Because operation of each model depends on the manufacturers seat and disc design, results obtained by the user may vary.

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Type of Steam trapsc. Ball Float Trap: Ball floats widely used as process traps. The valve seat is always submerged under water preventing any steam loss. The discharge is continuous and modulates with the condensing rate. It is unaffected by changes in inlet pressure.

d. Inverted Bucket Trap: Their discharge is intermittent. Requires priming at start up.

Other Terminologies associated with Traps :Flash SteamCondensate Recovery system (Open / Close)Back pressureContinuous Discharge / Intermittent DischargeSub coolingProcess Traps & Piping Traps (Drip Leg)

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Steam trapsActivities for Procurement : Process Traps are identified on P&ID Process Dept. issues Process Data sheet (PDS) for these traps. Piping Traps are identified by Piping Layout engineers Process data for Piping Traps are requested from Process by PipingPiping Material Engineer prepares final data sheet for both Process & Piping traps based on Process data & application.This data sheet is attached with MR & issued for inquiry.Once the offers from vendors are received, suitability of type of Trap is verified with vendors & if required, based on vendors experience; type may be changed during evaluation process; before finalisation of order.After Placement of order; Vendor Drawing Approval is mandatory.7/9/2013Introduction to Piping Materials5Strainers2. Strainers : Composed of BodyScreening element (Mesh)Supporting element for screen (Perforated Plate etc.)

Type of StrainerY-Strainers : Take their name from their configuration. They are typically used in application where the amount of solids to be removed is small, and where frequent clean-out is not required.

b) Tee strainers is a custom fabricated compound strainer designed to remove foreign particles from pipeline. Basically it contains the body as a standard Tee which carries a screening element with required supporting element.

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Type of Strainerc) Temporary Strainers : In various styles (Baskets, Cones, Cone type baskets, Plate) which are designed to provide inexpensive protection for pumps, meters, valves and other mechanical equipment.

d) Basket Strainers : The screen is in the form of a basket, with a lifting handle, so that all particulate captured and retained by the screen can be easily removed for disposal. They are intended for applications where large amounts of solids particulate are expected and where the clean-out will be frequent.

Other Terminologies associated with Strainers : Mesh No. Perforate Plate configuration (Square & Triangular Pitch) Open Area RatioPressure Drop across the strainerClogged Condition

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Strainer Activities for Procurement : Strainers are identified on P&ID. Piping Dept. makes the List Process Dept. issues Process Data sheet (PDS)Open Area Ratio & Pressure Drop Calculation based on given process data is done by Piping Material Engineer. If not found suitable; discussion with process is done. Final data sheet is prepared by Piping Material engineer which includes flow configuration in case of T-type strainer. For deciding this, respective layout engineer is consulted for each strainer Tag.This data sheet is attached with MR & issued for inquiry.Once the offers from vendors are received, open area ratio & pressure drop calculation submitted by vendor for offered strainers are verified. If not found satisfactory suitable / possible design change is done.After Placement of order; Vendor Drawing Approval is mandatory.

7/9/2013Introduction to Piping Materials8Flexible Hoses & Hose Couplings Application Service Stations / FillingUtility Stations around the column

Selection Basis Service fluidDesign conditions Application

Types of Hoses MetallicNon Metallic

Available End connections FlangedCoupling which are in turn threaded type, Quick Coupling, Cam Lock type etc.

7/9/2013Introduction to Piping Materials9Flexible Hoses & couplings7/9/2013Introduction to Piping Materials10

Flexible Hoses & couplings Activities for Procurement : Hoses are identified by Process & Data sheets are issued by Process Department Piping Department may add utility hoses as per their requirement & send request to process for process data required for these hoses. Based on PDS; Piping Material Engineer prepares data sheet adding suitable end connections & verifies material. Length requirement & quantity are also added by material engineer after discussing with Layout Engineer.Final data sheet is attached with MR & issued for inquiry.Once the offers from vendors are received, material suitability for given service fluid & design conditions are verified with Vendor. Also, end connections are selected based on the requirement; from various available vendors design. After Placement of order; Vendor Drawing Approval is mandatory.

7/9/2013Introduction to Piping Materials11Sight Glass As the name suggests, Sight Glass is to visualize the presence / nature of fluid flowing inside the pipe.

Components Housing (Metallic)Glass (Borosilicate toughened Glass Tube)End Connections (Flanged, SW, Threaded)Gaskets / O-rings / Seal rings for leak tightnessFlow Indicating Element (Rotar, float etc.)

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Sight GlassActivities for Procurement : Sight glasses are identified on P&ID. Process Dept. issues Process Data sheet (PDS) for the same. Based on PDS; Piping Material Engineer prepares Data sheet for Sight Glass adding Type, Material standard & other requirements.Final data sheet is attached with MR & issued for inquiry.Once the offers from vendors are received, Type of Sight Glass is verified with vendor for given service fluid & design parameters. Type may be changed based on vendors input.After Placement of order; Vendor Drawing Approval is mandatory.

7/9/2013Introduction to Piping Materials13Flame Arrester Application : To protect the equipment / line from fire by quenching the flame Type :Deflagration typeDetonation typeIn-lineEnd of Line

Design Standard EN 12874 : Excerpts from EN 12874 (ISO 16852) for selection of Flame Arrester :

1. Service Provide a brief description of the intended use for the flame arrester.

2. Analysis of gases or vapour & properties of the sameProvide full details of flammable and non-flammable components; which will allow the correct flame arrester design, explosion group and choice of materials to be made. Property includes density of mixture etc.

7/9/2013Introduction to Piping Materials14Flame Arrester3. Flow rate This should be in volumetric terms, or sufficient information provided to allow a volumetric flow rate to be calculated. For storage tank applications the inbreathing and outbreathing requirements should be given, or sufficient information on the tank type, pressure resistance shape, dimensions, fill and empty rates provided to enable these parameters to be calculated.

4. Temperature & Pressure ranges For both design and operating conditions, the maximum and minimum temperatures will allow the correct element and mechanical design of the flame arrester housing to be made. The maximum pressure at which a flammable mixture can ignite in the process should be highlighted if this is different to the normal operating pressure. For storage tank applications the pressure and vacuum requirements should be given.

5. Allowable pressure drop This will enable the correct flame arrester configuration to be provided and is determined from the volumetric flow rate.

7/9/2013Introduction to Piping Materials15Flame Arrester6. Type Specify in-line, end-of-line, pre-volume, short time or endurance burning safe and stable / unstable detonation as required. For in-line types details of the piping between the flame arrester and possible source of ignition should be supplied in the form of a dimensional sketch or isometric drawing.

7. Pipe Size, End Connections & Orientation The nominal size of the connecting pipework, end connection details (flanged / screwed), along with intended orientation of the flame arrester.

8. Housing material & Element materialState the preferred material of construction; based on the piping class & also shall be verified by manufacturer for suitability to the given mixture composition at given operating conditions.

9. Documentation State documentation requirements.7/9/2013Introduction to Piping Materials16Flame ArresterActivities for Procurement :Flame Arresters are identified on P&ID.Process Dept. issues Process Data sheet (PDS) for the same.Based on PDS; Piping Material Engineer prepares Data sheet for Flame Arrester adding Type, Material standard & other requirements.Final data sheet along with location of Flame Arrester (For In-Line type) is attached (in the form of Isometric) with MR & issued for inquiry.Once the offers from vendors are received, Type of Flame Arresters are verified with vendor for given design parameters. Type may be changed based on vendors input.After Placement of order; Vendor Drawing Approval is mandatory.7/9/2013Introduction to Piping Materials17Sample CoolerApplication : To cool the samples to the temperature as required.

Components : Housing Normally Carries Cooling Medium Tube / Coil Normally carries process medium Inlet / Outlet Nozzles Supporting structural Element

Activities for Procurement :Sample Coolers are identified on P&ID.Process Dept. issues Process Data sheet (PDS) for the same.Based on PDS; Piping Material Engineer prepares Data sheet for Coolers adding, Material standard & other requirements.Final data sheet along is attached with MR & issued for inquiry.Once the offers from vendors are received, design of Sample Cooler is verified with vendor for given design parameters.After Placement of order; Vendor Drawing Approval is mandatory.7/9/2013Introduction to Piping Materials18